1. Field of the Invention
The present invention relates to a beam forming apparatus. More particularly, the present invention relates to an apparatus and method for forming a beam for processing a radar signal.
2. Description of the Related Art
A radar signal is a representative electromagnetic wave signal, has intrinsic signal characteristics in time, frequency, and space areas according to a peripheral environment, and various techniques for such a radar signal processing have been researched. Radar signal processing requires an intrinsic algorithm and structure, unlike a generally well-known voice or image signal processing field, and should extract target information by processing a signal of a high speed and a large capacity in real-time for a given beam scan time.
In a radar system, an antenna provides an external image, and performance thereof becomes a decisive element for quality of an image. As quality of information increases and information gradually becomes complex, a request for improvement of antenna performance further increases. In such a situation, new digital beamforming (DBF) may be, an excellent technique for improving antenna performance.
Beamforming represents forming of a large directional antenna shape by combining propagation signals from arrangement of small nondirectional antennas. In beamforming, because a direction of a formed antenna beam may be electromagnetically set, in wireless communication, by directing an antenna in a signal source direction, beamforming is used for reducing interference and enhancing communication quality and may be used in an application field that searches for a direction of a signal source.
In general, a DBF apparatus receives a digital signal from an array antenna and has a structure that performs spatial processing of the signal, and an array antenna transmits electromagnetic waves at many locations at an opening surface of the antenna, and by converting and processing signals that are received by each receiving element to a complex digital signal, the DBF apparatus outputs a set of beams having different directions in space. Particularly, when processing a received signal, weight values are multiplied by signals of each antenna and these signals are added and used. However, by generating a signal for beamforming by processing in parallel signals of an antenna, it is difficult to apply such a method of forming a beam to a radar system in which the number of radar beams variably changes and a structure thereof becomes further complex.